.\" -*- nroff -*-
.\" Copyright 2010 Cisco Systems, Inc.  All rights reserved.
.\" Copyright 2006-2008 Sun Microsystems, Inc.
.\" Copyright (c) 1996 Thinking Machines Corporation
.\" Copyright (c) 2020      Google, LLC. All rights reserved.
.\" $COPYRIGHT$
.TH MPI_Address 3 "#OMPI_DATE#" "#PACKAGE_VERSION#" "#PACKAGE_NAME#"
.SH NAME
\fBMPI_Address\fP \- Gets the address of a location in memory -- use of this routine is deprecated.

.SH SYNTAX
.ft R
.SH C Syntax
.nf
#include <mpi.h>
int MPI_Address(void *\fIlocation\fP, MPI_Aint\fP *address\fP)

.fi
.SH Fortran Syntax
.nf
INCLUDE 'mpif.h'
MPI_ADDRESS(\fILOCATION\fP,\fI ADDRESS\fP,\fI IERROR\fP)
	<type>	\fILOCATION\fP (*)
	INTEGER	\fIADDRESS\fP,\fI IERROR\fP


.fi
.SH INPUT PARAMETER
.ft R
.TP 1i
location
Location in caller memory (choice).

.SH OUTPUT PARAMETERS
.ft R
.TP 1i
address
Address of location (integer).
.ft R
.TP 1i
IERROR
Fortran only: Error status (integer).

.SH DESCRIPTION
.ft R
Note that use of this routine is \fIdeprecated\fP as of MPI-2. Please use MPI_Get_address instead.
.sp
The address of a location in memory can be found by invoking this function. Returns the (byte) address of location.
.sp
Example: Using MPI_Address for an array.
.sp
.nf
REAL A(100,100)
.fi
.br
   INTEGER I1, I2, DIFF
.br
   CALL MPI_ADDRESS(A(1,1), I1, IERROR)
.br
   CALL MPI_ADDRESS(A(10,10), I2, IERROR)
.br
   DIFF = I2 - I1
.br
! The value of DIFF is 909*sizeofreal; the values of I1 and I2 are
.br
! implementation dependent.
.fi

.SH NOTES
.ft R
This routine is provided for both Fortran and C programmers and may be useful when writing portable code. In the current release, the address returned by this routine will be the same as that produced by the C & operator.
.sp
C users may be tempted to avoid using
MPI_Address and rely on the availability of the address operator &.
Note, however, that & cast-expression is a pointer, not an address.
ANSI C does not require that the value of a pointer (or the pointer
cast to int) be the absolute address of the object pointed at although
this is commonly the case. Furthermore, referencing may not have a unique
definition on machines with a segmented address space. The use of
MPI_Address to "reference" C variables guarantees portability to
such machines as well.

.SH ERRORS
Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument.
.sp
Before the error value is returned, the current MPI error handler is
called. By default, this error handler aborts the MPI job, except for I/O function errors. The error handler
may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.

.SH SEE ALSO
MPI_Get_address
.br
